1. Department
of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
2. Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
3. Department
of Pharmacology and Chemical Biology, University of Pittsburgh Cancer
Institute, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, United States